This invention relates, in general, to the field of therapeutic beds, and more particularly, to a bed provided with a mechanism for inducing waves along the length thereof, for treatment and prevention of pressure sores.
The problem of pressure sores, also known as decubitus ulcers or bed sores, has long been of concern for patients who are confined to bed for extended periods of time. The problem has been discussed recently in an article by Joanne M. Sammer, Taking The Pressure Off, published in the April, 1989, issue of Rx Home Care, pages 28 and 29, as well as in the more extensive article Guidelines For Home Air-Fluidized Bed Therapy, published by the United States Department of Health and Human Services in the Health Technology Assessment Reports, 1989, No. 5, by Kay Nimit M.D.
Ms. Sammer discusses the various stages of ulcers which may form in the skin, stage 1 being the least serious and stage 4 being the deepest ulcer; the damage occurring and worsening if pressure against the skin is greater than 32 mm/Hg for more than two hours. Many factors complicate the problems of pressure sores, including the patient's extreme weight or fragility, which make a patient more difficult to turn at regular intervals, or other health complications such as diabetes. Each patient's conditions are different and thus may require a different sort of care. The Health and Human Services article discusses one method of dealing with pressure sores. Air-fluidized bed therapy (AFBT) involves "flotation" of a body on fine ceramic beads which have been set in motion by a flow of warm pressurized air. Although initially developed for use in hospitals, AFBT is also being used by individuals in the home.
Other methods have been devised also for treating and preventing pressure sores in bed-ridden patients. For example, U.S. Pat. No. 3,656,190 to Regan et al shows a bed having multiple piston-like support elements which conform to the shape of the body and may be moved sequentially so as to provide a wave-like effect along the length of the body. A similar patent, U.S. Pat. No. 3,999,234 also to Regan teaches vertical piston-like elements which adapt to the shape of the body and have a spring element incorporated therein.
By contrast, U.S. Pat. No. 4,267,610 to Blakeway et al illustrates a therapeutic body support having a series of side by side rollers which move in unison back and forth and are covered by a sheet to separate the rollers from the user. U.S. Pat. No. 4,494,260 to Olds et al shows a similar idea where, rather than rollers, horizontal, transverse support blocks of foam or other resilient material are mounted on carriers which oscillate back and forth in unison along the upper surface of the bed to provide varied pressure to a body thereon. Likewise, the U.S. Pat. No. 4,625,487 to Blakeway illustrates tiltable parallel elements such as cushions. However, the support elements of Blakeway '487 are capable of movement in opposed directions, rather than all moving simultaneously, as in Olds et al.
U.S. Pat. No. 4,769,864 to Park illustrates a very simple therapeutic bed consisting of elongated tensile, tubular wires which pass back and forth across the width of the bed and, although strung tightly, allow some "give" for a massaging action to a body thereon.
More recently, U.S. Pat. No. 4,799,276 to Kadish teaches another vertical piston form of a therapeutic bed in which valves are provided associated with and controlling the discharge of air from piston chambers under pressure applied to each of the respective support pistons. After a preset time and level of pressure prevailing, air is discharged from the piston chamber to allow downward displacement of the respective piston.
Among other efforts of the prior art to provide beds which will prevent decubitus ulceration from occuring, there have been proposed various rocking beds, warm air-fluidized beds, and proposals for the use of various types of flotation cushions. Such prior apparatuses typically have been undesirably expensive and complicated. Other difficulties of the prior art may also be noted. For example, the use of air-fluidization technique is likely to cause patient dehydration, and the air-fluidized bed also presents difficulty of the patient tending to "float" upon the surface. This presents further difficulty for care attendants in that the patient is difficult to turn and may tend to sink into the bed. Another difficulty inherent in such prior art constructions which provide patient movement such as by rocking, is that the patient may incur nausea. Further, the rocking type of bed, in its moving of the patient back and forth, is likely to interfere with other patient activities such as work or tasks involving the need for eye fixation on a particular person or thing.
A further limitation of the prior art, particularly the rocking bed, is that the apparatus is visually intimidating and imposing, and thereby is psychologically undesirable. That is, the apparatus does not look like a "regular" bed.
Accordingly, it is among the objects of the present invention to provide a method and apparatus for carrying out the method for prevention and/or treatment of pressure sores in bed-ridden persons. It is intended that the present invention be relatively simple to manufacture and operate as well as being relatively inexpensive, yet capable of providing variable conditions of movement depending on the needs and preferences of the particular patient. Moreover, it is intended that the above objects be achieved without inducing nausea in the patient or creating other risks to the patient, such as from burns or dehydration. Moreover, it is desired to provide such an apparatus which can be easily cleaned and may be quickly disassembled and reassembled for that purpose.
Among still further objects of the present invention may be noted the provision of such apparatus which, in addition to its relative mechanical simplicity, looks like a "regular" bed and so is psychologically advantageous for the patient and others who may have dealings with the patient; which is adjustable in different ways to provide different possible effects, as by adjustment in the amplitude of movement of its members and adjustment of the speed of operation.
Among still further objects of the invention may be noted the provision of such apparatus and method which brings about a natural systolic-diastolic variation in pressure upon the body, and in doing so, provides what is in actuality a traveling wave along the surface of the bed which provides a pumping action with such systolic-diastolic variation, is very much like the normal heart action. Thus, it is among the objects of the invention to provide such a method and apparatus which is highly therapeutic and beneficial to the patient.
Accordingly, in furtherance of the above objects, the present invention is, briefly, a therapeutic bed including a body support means having first and second ends and extending longitudinally therebetween. The new bed includes wave production means for causing transverse waves to repetitively form and travel at a predetermined amplitude and a predetermined periodicity along a longitudinal axis of the body support means from the second end to the first end thereof. Use of the new bed permits a decrease in the occurrence of pressure sores upon a body supported on a bed by periodically varying the pressure asserted along the length of the body support means against the body supported thereon.
The present invention also comprises briefly, a method for decreasing the incidence of pressure sores in a person supported by a bed for an extended time intervals. The method includes supporting the person longitudinally upon a bed having a longitudinal axis, first and second opposing ends, and a support surface extending therebetween. The method further includes repetitively causing transverse waves to be formed and to travel at a predetermined amplitude and a predetermined periodicity along the length of the bed body support surface from the second end to the first end of the bed. The new method permits periodically varying the pressure asserted by the bed against the body supported thereon.
Other objects and features will be in part apparent and in part pointed out hereinbelow.